In recent years, health professionals have complained of shortages of nurses. If policymakers and planners in the health care industry are going to obtain the necessary nurses in terms of numbers and geographic distribution, they must understand the factors causing nurses to offer, or not to offer, their services. That is, "what are the determinants of the supply of nurses?" Important factors are economic - both monetary and nonpecuniary - and noneconomic in nature. An understanding of the determinants of nurse labor supply is likely to become even more important as the country moves toward the adoption of a national health insurance plan. The basic objectives of our current work for PHS (Grant number 5 RO2 NU00576-02 NRE) as well as the proposed extension involve providing insights into the empirical significance, in the context of a multivariate model of the nurse labor market, of numerous demographic, socio-economic and environmental characteristics. The proposed extension will include estimates of the influence of nurse labor-market-structure (an environmental characteristic) on labor supply and the wage-condition of nurse employment. In a previous study, employing the 1 in 100 sample from the 1970 Census (see Link and Settle 1977, included in an appendix to this proposal), we estimate labor supply parameters for married registered nurses (RNs). Since licensed practical nurses (LPNs) are substitutable for RNs in many tasks, policymakers must also understand the nature of the labor market for LPNs. Notably, we are unable to find any econometric studies of the LPN labor market. This proposed research will help to fill this void by providing estimates of labor supply parameters for married well as single female LPNs using the 1970 Census data. In addition, we extend our earlier study of RNs to those who are single.